diff -urN trac-0.10.3/trac/db/postgres_backend.py trac-0.10.3.unixsocket/trac/db/postgres_backend.py
--- trac-0.10.3/trac/db/postgres_backend.py	2006-12-12 18:44:07.000000000 +0000
+++ trac-0.10.3.unixsocket/trac/db/postgres_backend.py	2007-01-16 06:27:04.148000250 +0000
@@ -95,6 +95,8 @@
             except ImportError:
                 from pyPgSQL import PgSQL
                 from pyPgSQL.libpq import OperationalError as PGSchemaError
+        if params.has_key('host'):
+            host = params['host']
         if psycopg:
             dsn = []
             if path: